The cracks in Mars’ surface may be the fossilized remains of a web of water, according to new research released Tuesday.

The findings, accepted for publication in Geophysical Research Letters, may explain a mysterious network of ridges that vein across the Red Planet’s subsurface -- describing a watery underground that may be an ideal spot to search for evidence of past life.

Researchers from Brown University used data from the Mars Reconnaissance Orbiter to examine more than 4,000 of these strange ridges across two crater-pocked areas, the Nilosyrtis highlands and the Nili fossae area, studying the ridges’ orientations and the composition of the rocks.

The ridges probably started out as the cracks from impact craters, the researchers concluded, an idea bolstered by the fact that the ridges’ orientation seems to match those of the craters where they’re found. And they seem to appear only in areas where the rock is rich in iron-magnesium clay – a mineral that signals the past presence of water.

Water must have filled the crater-caused cracks, the scientists reasoned, depositing mineral as it flowed through – and those deposits, stronger than the surrounding rock, could withstand the withering effects of erosion as the rest of the rock was worn away, leaving those mineral-filled cracks exposed.

The study on these fossil waterways comes little more than a week after a paper in the journal Nature Geoscience that looked at a possible ancient crater lake and argued that it could hold signs of life from beneath the Martian surface.

The finding comes as the NASA Curiosity rover roams the Red Planet, looking for the ingredients for life.